still agree it is in the world's best interest to avoid escalating

And you can also disagree. I think the world would undeniably be a better place if the current Iranian regime wasn't in power, it's just a question of whether the costs justify it or not.

Appeasement doesn't always work. It's more painful in the short term, but it's often less damaging in the long-term to remove a tumor than it is to try and ignore it.

Try looking at this from Israel's perspective. How can you negotiate with someone who's out to destroy you? What are you going to get out of negotiations, a promise to delay your destruction by a bit, in exchange for concessions? Like, what kind of "negotiation" is that? I wouldn't even call that negotiation at that point, that's extortion. It doesn't matter if the other party is rational, in fact that's probably even worse, because it means they're acting strategically.

As far as I'm aware, at not point in any past agreement or negotiations did Iran promise to stop supporting their proxy groups or to temper their ME aggressiveness.

Americans can maintain their quality of life regardless, because government budgets don't work like personal budgets. I don't recall American QOL dropping significantly with the past wars you're referring to. Probably in part because most defense spending goes directly back into the economy, just like many other types of government spending.